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Prentice's rule, named so after the optician Charles F. Prentice, is a formula used to determine the amount of induced prism in a lens: = where: P is the amount of prism correction (in prism dioptres) c is decentration (the distance between the pupil centre and the lens's optical centre, in millimetres)
Amblyopia. Anisometropia is a condition in which a person's eyes have substantially differing refractive power. [1] Generally, a difference in power of one diopter (1D) is the threshold for diagnosis of the condition . [2] [3] Patients may have up to 3D of anisometropia before the condition becomes clinically significant due to headache, eye ...
Cauchy's two-term equation for air, expanded by Lorentz to account for humidity, is as follows: n a i r ( λ , T , v , p ) ≈ 1 + 77.6 ⋅ 10 − 6 T ( 1 + 7.52 ⋅ 10 − 3 λ 2 ) ( p + 4810 v T ) {\displaystyle n_{air}(\lambda ,T,v,p)\approx 1+{\frac {77.6\cdot 10^{-6}}{T}}\left(1+{\frac {7.52\cdot 10^{-3}}{\lambda ^{2}}}\right)\left(p+4810 ...
After simplifying the final equation is found: F F c = 1 − x F ⇒ F c = F 1 − x F = 1 1 F − x ⇒ F = 1 1 F c + x {\displaystyle {\begin{aligned}&&{\frac {F}{F_{\text{c}}}}&=1-xF\\&\Rightarrow &F_{\text{c}}&={\frac {F}{1-xF}}={\frac {1}{{\frac {1}{F}}-x}}\\&\Rightarrow &F&={\frac {1}{{\frac {1}{F_{\text{c}}}}+x}}\end{aligned}}}
Description. Mathematically, such a calculation can be expressed: The bolometric correction for a range of stars with different spectral types and groups is shown in the following table: [1] [2] [3] The bolometric correction is large and negative both for early type (hot) stars and for late type (cool) stars.
Esophoria is an eye condition involving inward deviation of the eye, usually due to extra-ocular muscle imbalance. It is a type of heterophoria. Cause. Causes include: Refractive errors; Divergence insufficiency; Convergence excess; this can be due to nerve, muscle, congenital or mechanical anomalies.
Esotropia is a form of strabismus in which one or both eyes turn inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. [1] It is the opposite of exotropia and usually involves more severe axis deviation than esophoria. Esotropia is sometimes erroneously called ...
Minimum deviation. In a prism, the angle of deviation ( δ) decreases with increase in the angle of incidence ( i) up to a particular angle. This angle of incidence where the angle of deviation in a prism is minimum is called the minimum deviation position of the prism and that very deviation angle is known as the minimum angle of deviation ...
The Prentice position is an orientation of a prism, used in optics, optometry and ophthalmology. In this position, named after the optician Charles F. Prentice, the prism is oriented such that light enters it at an angle of 90° to the first surface, so that the beam does not refract at that surface. All the deviation caused by the prism takes ...
The Redlich–Kwong equation is formulated as: [1] [3] where: p is the gas pressure. R is the gas constant, T is temperature, Vm is the molar volume ( V / n ), a is a constant that corrects for attractive potential of molecules, and. b is a constant that corrects for volume.